Decoding the dials

Any idea what those little letters and symbols next to "Swiss Made" at the bottom of your watch dial mean?







The "O" means the numerals are gold.
The "T" means the numerals are luminous and contain Tritium.
The "T<25" means that the amount of Tritium is less than the legal limit (tritium is a radioactive substance afterall).

Read more about it here.